Interactive input systems that allow users to input ink into an application program using an active pointer (e.g., a pointer that emits light, sound or other signal), a passive pointer (e.g., a finger, cylinder or other object) or other suitable input device such as for example, a mouse or trackball, are well known. These interactive input systems include but are not limited to: touch systems comprising touch panels employing analog resistive or machine vision technology to register pointer input such as those disclosed in U.S. Pat. Nos. 5,448,263; 6,141,000; 6,337,681; 6,747,636; 6,803,906; 7,232,986; 7,236,162; and 7,274,356 and in U.S. Patent Application Publication No. 2004/0179001 assigned to SMART Technologies ULC of Calgary, Alberta, Canada, assignee of the subject application, the contents of which are incorporated by reference; touch systems comprising touch panels employing electromagnetic, capacitive, acoustic or other technologies to register pointer input; tablet personal computers (PCs); touch-enabled laptop PCs; personal digital assistants (PDAs); and other similar devices.
Interactive input systems provide users with great flexibility to process electronic documents. Electronic document processing software programs are known that allow users to incorporate and manipulate mathematical objects, such as equations, tables, and graphs, in electronic documents. For example, Microsoft Excel™ software allows users to enter characters and numbers into the cells of a spreadsheet, and generate a graph, such as a bar chart, line curve or pie chart, from the content of the cells the user selected. When the user changes the content of a cell that is used to generate the graph, the graph is automatically updated. When a graph is selected, the cells that the graph is generated from are also marked with highlighted border (see FIG. 1).
When using Microsoft Excel™, a user has to select a graph and then identify the cells with highlighted border to locate the cells that the graph was generated from, which may be difficult for the user. When the cells with highlighted border are located beyond the Microsoft Excel™ window, the user has to move around the entire spreadsheet to find the cells with highlighted border. Moreover, if these cells are under a graph, it is almost impossible for the user to find their location.
U.S. Pat. No. 7,289,120 to Fukaya teaches a graphic display control apparatus that has a geometrical window and a formula window. A formula string in the formula window can be dragged/copied from the formula window and dropped/pasted into the geometrical window to draw a graph of the formula, and vice versa. A link may also be created between the formula in the formula window and the graph in the geometrical window so that when the user changes the formula in the formula window or the graph in the geometrical window, respectively, the graph in the geometrical window or the formula in the formula window will be automatically updated. A mark may be added to the proximity of a formula to indicate that the formula is linked (instead of copied) to the geometrical window. However, U.S. Pat. No. 7,289,120 does not teach how a user can distinguish such a mark from other similar marks and how to identify the source data of a graph when multiple geometrical windows and formula windows exist in the same display screen.
The functionality of the aforementioned methods is also limited. For example, they do not allow the user to separate a graph or a geometrical window, respectively, from the cells or formula window it is linked to. Moreover, they do not allow the user to relate two mathematical objects of the same type (e.g., relating two graph objects).
Therefore, there is a need to provide a novel method of linking and managing mathematical objects in an interactive input system and a novel interactive input system executing the method.